Conventionally, an example of known techniques related to the heat sink structure applied to electronic control devices of this kind is “housing having a built-in circuit board” (see Patent Document 1) in which part of a heat dissipating fin is exposed from part of the housing, the circuit board having an electronic component thereon is provided so as to touch the heat dissipating fin via a heat dissipating sheet, and the circuit board, the heat dissipating sheet, and the heat dissipating fin are integrally formed with the housing by sealing them with sealing plastic by insert molding or the like.
Another known technique related to similar heat sink structures is “electric component casing structure” (see Patent Document 2) in which an electric component casing for housing a circuit board having an electronic electric component thereon in a sealed manner is constructed by a dual-layer structure comprising a resin casing section formed of resin and a metal casing section formed of metal, and the resin casing section and the metal casing section are integrally formed by outsert molding or insert molding.